Azo dyestuffs



Patented May 17, 1938 UNITED STATES AZO DYESTUFFS Hans Krzikalla and Paul Garbsch, Ludwigshafenonthe-Rhine,

General Aniline Works, Inc., New York, N. Y., a corporation of Delaware No Drawing. Application November 13, 1936, Serial No. 110,638. In Germany November 23,

8 Claims.

wherein R stands for an aliphatic radicle attached to the nitrogen atom by means of a -CHzgroup and containing at least one oxygen atom, and. wherein X and Y are radicles of the benzene series, which may be substituted by halogen, alkyl, oxalkyl, amino or nitro groups, but there must remain in the ring Y at least one position capable of coupling.

The aliphatic radicle may be for example a hydroxyethyl, hydroxypropyl or dihydroxypropyl radicle, or a hydroxyethyl alkyl ether, hydroxyalkyl oxalkyl ether, or hydroxy alkyl ester radicle.

Suitable compounds of the said kind may be prepared for example by the addition of one, two, three or more molecular proportions of ethylene oxide to N-benzylanilines. The oxalkyl compounds thus obtained may be converted into the corresponding ethers or esters by treatment with alkylating agents, such as toluene-sulphonic acid alkyl esters, or with acetic-acid anhydride, respectlvely.

The dyestuffs obtained according to our invention are especially suitable for dyeing cellulose esters and ethers. They may also be used for coloring paraifin wax and stearine and also, by reason of their good solubility in organic solvents, for the preparation of colored spirit and cellulose ester lacquers. The dyestuffs have a good fastness to sublimation and'are therefore also very suitable for use as double-tone and intaglio printing inks.

The following examples will further illustrate how this invention may be carried out in practice but the invention is not restricted to these examples. The parts are by weight.

Example 1 The diazo compound of 139 parts of l-amino- 4-nitrobenzene is coupled with a solution of 240 parts of N-hydroxyethyl-N-benzylaminobenzene in 3000 parts of water and 170 parts of concentrated hydrochloric acid. A dyestuff is thus obtained which colors nitrocellulose ester lacquers brilliant red shades of good fastness to light.

The dyestuff may be dissolved in benzene and PATENT OFFICE Germany, assignors to treated with acetic acid anhydride. The acylated dyestuif thus obtained colors nitrocellulose lacquers similar red shades. The same dyestuff is obtained if N-acetohydroxyethyl-N-benzylani1ine be used instead of N-hydroxyethyl-N-benzylaniline.

If N-hydroxyethyl-N- (4nitrobenzyl) -aminobenzene be used as the coupling component, a dyestuff having similar properties and a somewhat more yellow shade is obtained.

Example 2 A solution of 240 parts of N-hydroxyethyl-N- benzylaminobenzene in 3000 parts of water and 170 parts of concentrated hydrochloric acid isallowed to flow into the diazo solution of 172 parts of l-amino-2-chlor-4-nitrobenzene while stirring. A dyestuff is obtained which colors nitrocellulose ester lacquers red shades.

If the addition compounds derived from 2, 3 or even more, as for example 10 or 12 molecular proportions of ethylene oxide and 1 molecular proportion of N-benzylaminobenzene or N-dlhydroxy-propyl-N-benzylaminobenzene be used as coupling component instead of N-hydroxyethyl-N-benzylaminobenzene, dyestuffs having similar properties are obtained.

Example 3 The diazo compound of 207 parts of l-amino- 2.5-dichlor-4-nitrobenzene or lamino2.6-dlchlorl-nitrobenzene is poured onto ice and there is added thereto a solution of 240 parts of N- hydroxyethyl N benzylaminobenzene in 5000 parts of Water and 1'70 parts of concentrated hydrochloric acid. The dyestuifs thus obtained color nitrocellulose ester lacquers reddish shades if 1-amino-2.5-dich1or-4nitrobenzene has been used as the diazo component or brown shades if 1-amino-2.6-dichlor-4-nitrobenzene has been used as the diazo component. The dyestuffs have a good fastness to sublimation and are therefore also specially suitable for use for double-tone and intaglio printing inks.

If N-hydroxyethyl-N-benzyl-ortho toluidlne be employed instead of N-hydroxyethyl-N-benzylaniline azo dyestuffs having similar properties are obtained.

What we claim is:-

1. A20 dyestuffs corresponding'to the general formula wherein It stands for an aliphatic radicle attached to the nitrogen atom by means of a CH2- group and containing at least one oxygen atom, wherein X and Y stand for radicles of the benzene series, and wherein A stands for a radicle of the benzene series, the dyestuffs being free from sulphonic and carboxylic acid groups.

2. Azo dyestufis corresponding to the general formula wherein R stands for an aliphatic radicle at-' tached to the nitrogen atom by means of a CH2 group and containing at least one oxygen atom, and wherein A stands for a radicle of the benzene series, the dyestufis being free from sulphonic and carboxylic acid groups.

3. A20 dyestuffs corresponding to the general formula wherein 22 stands for a whole number and wherein A stand for a radicle of the benzene series, the dyestuffs being free from sulphonic and carboxylic acid groups.

4. Azo dyestufis corresponding to the general formula wherein A stands for a radicle of the benzene series, the dyestuffs being free from sulphonic and carboxylic acid groups.

5. A20 dyestufis corresponding to the general formula wherein A stands for a radicle of the benzene series substituted by a nitro group in para-position to the azo group, the dyestuffs being free from sulphonic and carboxylic acid groups.

6. The azo dyestuff of the formula CHzCHaOH 7. The azo dyestufi of the formula 8. The azo dyestuff of the formula CHzCHzOH HANS KRZIKALLA. PAUL GARBSCH. 

